Maybe if the US opened the door to foriegn controllers they might be able to get some experience back into the FAA to replace what they are currently losing at a rapid pace.
Maybe if Eurocontrol did not discriminate against controllers from outside the EU (aussies, kiwis, canuks, seeth eefricans and others) they might also be able to stabilish their staffing levels and bring in some experience to their control centres.
Maybe if Hong Kong did not discriminate against experienced controllers (40+) then they might be able to bolster their controller numbers in the short term.
Yes, it takes at least 2 years to fully train an ab-intio student to licensed controller, preferable longer. In the past some companies have reduced ab-initio intake in an effort to reduce costs, looks good for the companies profits in the short term.
Fatal in the long term when they realise that they have a bunch of retirees coming up and they need replacement controllers, quickly, right now, where are they ?? 2 years to train some replacements, what, are you kidding me ??
But thats another story about HR and Bean-counters